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| United States Patent |
6,042,716
|
|
Morel
, et al.
|
March 28, 2000
|
Process for transforming a gas oil cut to produce a dearomatised and
desulphurised fuel with a high cetane number
Abstract
A process for transforming a gas oil cut into a dearomatized fuel with a
high cetane number comprises at least one first, deep desulphurization and
deep denitrogenation step in which the gas oil cut and hydrogen are passed
over a catalyst comprising a mineral support, at least one group VIB metal
or metal compound, at least one group VIII metal or metal compound, and
phosphorous or at least one phosphorous compound, and at least one
subsequent second step, dearomatization, in which the desulphurized and
denitrogenated product from the first step is passed with hydrogen over a
catalyst comprising a mineral support and at least one group VIII noble
metal or noble metal compound.
| Inventors:
|
Morel; Frederic (Francheville, FR);
Delhomme; Henri (Sainte-Foy-les-Lyon, FR);
George-Marchal; Nathalie (Paris, FR)
|
| Assignee:
|
Institut Francais du Petrole (Rueil Malmaison Cedex, FR)
|
| Appl. No.:
|
992486 |
| Filed:
|
December 18, 1997 |
Foreign Application Priority Data
| Current U.S. Class: |
208/89; 208/143; 208/210; 208/212; 585/264; 585/266; 585/269 |
| Intern'l Class: |
C10G 065/08; C10G 069/02 |
| Field of Search: |
208/89,212,143,210
585/264,266,269
|
References Cited
U.S. Patent Documents
| 3236764 | Feb., 1966 | Den Herder et al. | 208/210.
|
| 3356608 | Dec., 1967 | Franklin | 208/212.
|
| 3899543 | Aug., 1975 | Cosyns et al. | 208/89.
|
| 4225461 | Sep., 1980 | Cosyns et al. | 252/439.
|
| 4875992 | Oct., 1989 | Hammer | 208/89.
|
| 5110444 | May., 1992 | Haun et al. | 208/89.
|
| 5114562 | May., 1992 | Haun et al. | 208/89.
|
| Foreign Patent Documents |
| 0 297 949 | Jan., 1989 | EP.
| |
Primary Examiner: Griffin; Walter D.
Attorney, Agent or Firm: Millen, White, Zelano & Branigan, P.C.
Claims
We claim:
1. A process for transforming a gas oil cut into a diesel fuel having a
cetane number of at least 49, less than 100 ppm of sulphur, less than 200
ppm of nitrogen and less than 10% by volume of aromatic compounds,
comprising the following steps:
a) passing the gas oil cut and hydrogen under denitrogenation and
desulphurisation conditions in at least one step over a catalyst
comprising a mineral support, at least one metal or metal compound from
group VIB of the periodic table in a quantity, expressed as the weight of
metal with respect to the weight of finished catalyst, of about 0.5% to
40%, at least one metal or metal compound from group VIII of the periodic
table in a quantity, expressed as the weight of metal with respect to the
weight of finished catalyst, of about 0.1% to 30%, and phosphorous or at
least one phosphorous compound in a quantity, expressed as the weight of
phosphorous pentoxide with respect to the weight of the support, of about
0.001% to 20% to produce an at least partially denitrogenated and
desulfurised effluent;
(b) steam stripping the effluent from step (a) and, optionally, recycling
hydrogen therein for use in step (a);
(c) passing at least a portion of the steam stripped effluent from step (b)
with hydrogen under dearomatisation conditions over a catalyst comprising,
on a mineral support having at least one halogen, at least one noble metal
or noble metal compound from group VIII in a quantity, expressed as the
weight of metal with respect to the weight of finished catalyst, of about
0.01% to 20% to produce a denitrogenated, desulfurised and dearomatised
diesel fuel, and, optionally, recycling hydrogen for use in step (c);
with the further provision that fresh hydrogen is introduced into steps (a)
and (c) independently of each other and that recycle hydrogen from step
(b) is recycled to only step (a) and recycle hydrogen from step (c) is
recycled to only step (c).
2. A process according to claim 1, in which the operating conditions of
step a) include a temperature of about 300.degree. C. to about 450.degree.
C., a total pressure of about 2 MPa to about 20 MPa and an overall hourly
space velocity of the liquid feed of about 0.1 to about 10 h.sup.-1, and
those in step c) include a temperature of about 200.degree. C. to about
400.degree. C., a total pressure of about 2 MPa to about 20 MPa and an
overall hourly space velocity of about 0.5 to about 10 h.sup.-1.
3. A process according to claim 1, in which the catalyst in step a)
comprises at least one metal or metal compound selected from the group
consisting of molybdenum and tungsten and at least one metal or metal
compound selected from the group consisting of nickel, cobalt and iron.
4. A process according to claim 1, in which the catalyst in step a)
comprises molybdenum or a molybdenum compound in a quantity, expressed as
the weight of metal with respect to the weight of finished catalyst, of
about 2% to 30% and a metal or metal compound selected from the group
consisting of by nickel and cobalt in a quantity, expressed as the weight
of metal with respect to the weight of finished catalyst, of about 0.5% to
15%.
5. A process according to claim 1, wherein in step (a) the group VIII metal
is nickel and the group VIB metal is molybdenum.
6. A process according to claim 1, in which the catalyst of step a) further
comprises boron or at least one boron compound in a quantity of 10% or
less, expressed as the weight of boron trioxide with respect to the weight
of the support.
7. A process according to claim 1, in which the support for the catalysts
used in step a) and in step c) is selected independently of each other
from the group consisting of alumina, silica, silica-aluminas, zeolites,
titanium oxide, magnesia, boron oxide, zirconia, clays and mixtures of at
least two of these mineral compounds.
8. A process according to claim 1, in which the support for the catalyst of
step c) comprises about 0.5% to about 15% by weight of halogen, with
respect to the weight of the support.
9. A process according to claim 1, in which the support for the catalyst of
step c) comprises at least one halogen selected from the group consisting
of chlorine and fluorine.
10. A process according to claim 1, in which the support for the catalyst
of step c) comprises chlorine and fluorine.
11. A process according to claim 1, in which the catalyst of step c)
comprises at least one metal or metal compound selected from the group
consisting of palladium and platinum in a quantity, expressed as the
weight of metal with respect to the weight of finished catalyst, of about
0.01% to 10%.
12. A process according to claim 1, wherein the steam stripped effluent
passed into step c) has a sulfur content of less than 100 ppm.
13. A process according to claim 1, wherein the steam stripped effluent
passed into step c) has a sulfur content of less than 50 ppm.
14. A process according to claim 1, wherein step b) is the sole stripping
step.
Description
FIELD OF THE INVENTION
The present invention relates to fuels for internal combustion engines.
More particularly, it relates to the production of a fuel for compression
ignition engines. Within this field, the invention relates to a process
for transforming a gas oil cut to produce a dearomatised and desulphurised
fuel with a high cetane number.
BACKGROUND OF THE INVENTION
Gas oil cuts, whether straight run from a crude petroleum or from a
catalytic cracking process, currently still contain non negligible
quantities of aromatic compounds, nitrogen-containing compounds and
sulphur-containing compounds. The current legislation of the majority of
industrialised countries dictates that engine fuel must contain less than
500 parts per million (ppm) of sulphur. Some countries have no current
regulations which impose a maximum aromatics and nitrogen content.
However, several countries or states, like Sweden and California, are
known to be planning to limit the aromatics content to less than 20% by
volume, or even to less than 10% by volume, and some experts believe that
this limit could be 5% by volume. In Sweden in particular, certain classes
of diesel fuel must already satisfy very severe specifications. Thus in
that country, class II diesel fuel cannot contain more than 50 ppm of
sulphur and more than 10% by volume of aromatic compounds, and that of
class I cannot contain more than 10 ppm of sulphur and 5% by volume of
aromatic compounds. Class III fuel in Sweden must currently contain less
than 500 ppm of sulphur and less than 25% by volume of aromatic compounds.
Similar limits also apply for the sale of that type of fuel in California.
During this time, motorists in several countries have pressed for
legislation which will oblige gasoline producers to produce and sell a
fuel with a minimum cetane number. Current French legislation requires a
minimum cetane number of 49, but in the near future this minimum number
could be at least 50 (as is already the case for class I fuel in Sweden),
and probably at least 55; most probably it will be between 55 and 70.
A number of specialists are of the serious view that in the future the
nitrogen content will be regulated, to less than 200 ppm, for example, or
even less than 100 ppm. A low nitrogen content would improve the stability
of the products, which would be welcomed by both the product vendor and
the producer.
A reliable and efficient process thus needs to be developed, which process
can produce a product with improved characteristics regarding the cetane
number and the aromatics, sulphur and nitrogen content, from conventional
straight run gas oil cuts or those from catalytic cracking (LCO cut) or
from a different conversion process (coking, visbreaking, hydroconversion
of residues, etc.). It is particularly important, and this is one of the
advantages of the process of the present invention, to produce a minimum
of gaseous hydrocarbon compounds and to be able to produce an effluent
which is directly and integrally saleable as a very high quality fuel cut.
Further, the process of the present invention can be conducted over a long
period of time without the need for regeneration of the catalysts used,
which have the advantage of being very stable over time.
SUMMARY OF THE INVENTION
In its broadest scope, the present invention thus concerns a process for
Transforming a gas oil cut to produce a dearomatised and desulphurised
fuel with a high cetane number in at least two successive steps. It also
concerns the fuel obtained by this process.
More precisely, the present invention concerns a process for transforming a
gas oil cut into a dearomatised and desulphurised fuel with a high cetane
number, comprising the following steps:
a) at least one first step for deep desulphurisation and deep
denitrogenation in which the gas oil cut and hydrogen are passed over a
catalyst comprising a mineral support, at least one metal or metal
compound from group VIB of the periodic table in a quantity, expressed as
the weight of metal with respect to the weight of finished catalyst, of
about 0.5% to 40%, at least one metal or metal compound from group VIII of
the periodic table in a quantity, expressed as the weight of metal with
respect to the weight of finished catalyst, of about 0.1% to 30% and
phosphorous or at least one phosphorous compound in a quantity, expressed
as the weight of phosphorous pentoxide with respect to the weight of the
support, of about 0.001% to 20%; and
b) at least one subsequent second step for dearomatisation in which at
least a portion, preferably all, of the product from the first step which
has been at least partially and preferably completely desulphurised and
denitrogenated is passed with hydrogen over a catalyst comprising, on a
mineral support, at least one noble metal or noble metal compound from
group VIII in a quantity, expressed as the weight of metal with respect to
the weight of finished catalyst, of about 0.01% to 20%, and preferably at
least one halogen.
Advantageously, in accordance with the process, hydrogen is introduced at
each first and second step, and may be recycled to the first and second
steps, independently of each other, meaning that the gases from the two
steps are not handled together.
The effluent from the first step preferably undergoes steam stripping to
separate at least part of the gas phase, which may be treated and
optionally recycled at least in part to that step. At least a portion of
the product from the stripping step undergoes the second step of the
process of the invention.
The effluent from the final step is preferably steam stripped, is
advantageously passes into a coalescer and is optionally dried.
In a preferred implementation of the invention, the operating conditions of
steps a) and b) are selected as functions of the characteristics of the
feed which may be a straight run gas oil cut, a gas oil from catalytic
cracking or a gas oil from coking or visbreaking of residues, or a mixture
of two or more of these cuts so as to obtain a product containing less
than 100 ppm of sulphur and less than 200 ppm, preferably 50 ppm, of
nitrogen and the conditions of step b) are selected so that the product
obtained contains less than 10% by volume of aromatic compounds. These
conditions may be rendered more severe so as to obtain, after the second
step, a fuel containing less than 5% by volume of aromatic compounds, less
than 50 ppm or even less than 10 ppm of sulphur, less than 20 ppm, or even
less than 10 ppm of nitrogen, and with a cetane number of at least 50 or
even at least 55, generally in the range 55 to 60.
To obtain such results, the conditions of step a) include a temperature of
about 300.degree. C. to about 450.degree. C., a total pressure of about 2
MPa to about 20 MPa and an overall hourly space velocity of the liquid
feed of about 0.1 to about 10, preferably 0.1 to 4, and those in step b)
include a temperature of about 200.degree. C. to about 400.degree. C., a
total pressure of about 2 MPa to about 20 MPa and an overall hourly space
velocity of about 0.5 to about 10.
When a relatively low pressure range is desired while still producing
excellent results, a first step a1) can be carried out under conditions
which can reduce the sulphur content of the product to about 500 to 800
ppm, then this product can be sent to a subsequent step a2) the conditions
of which are selected to bring the sulphur content to a value which is
below about 100 ppm, preferably below about 50 ppm, and the product from
this step a2) is then sent to step b). In this implementation, the
conditions of step a2) are identical or, as is preferable, milder than
when a single step a) is used with a given feed, since the product sent to
this step a2) already has a greatly reduced sulphur content. In this
implementation, the catalyst in step al) can be a conventional prior art
catalyst such as that described in the text of our French patent
applications FR-A-2 197 966 and FR-A-2 538 813 and that of step a2) is
that described above for step a). The scope of the invention includes
using the same catalyst in steps a1) and a2).
In these steps a), a1) and a2), the catalyst support can be selected from
the group formed by alumina, silica, silica-aluminas, zeolites, titanium
oxide, magnesia, zirconia, clays and mixtures of at least two of these
mineral compounds. Alumina is most frequently used.
In a preferred implementation of the invention, the catalyst in these steps
a), a1), a2) will comprise, deposited on the support, at least one metal
or metal compound, advantageously selected from the group formed by
molybdenum and tungsten and at least one metal or metal compound
advantageously selected from the group formed by nickel, cobalt and iron.
The catalyst most frequently comprises molybdenum or a molybdenum compound
and at least one metal or metal compound selected from the group formed by
nickel and cobalt.
In a particular and preferred implementation of the invention, the catalyst
in steps a), a1) and a2) comprises boron or at least one boron compound,
preferably in a quantity of 10% or less, expressed as the weight of boron
trioxide with respect to the weight of the support, preferably deposited
on the support.
The quantity of group VIB metal or metal compound (preferably Mo),
expressed as the weight of metal with respect to the weight of finished
catalyst, is preferably about 2% to 30%, more preferably about 5% to 25%,
and that of the group VIII metal or metal compound (preferably Ni or Co)
is preferably about 0.5% to 15%, more preferably about 1% to 10%.
A catalyst containing Ni, Mo, and P is preferably used, the proportions of
these elements having been defined above, or more preferably Ni, Mo, P and
B.
A particularly advantageous catalyst is that described in European patent
EP-A-0 297 949, the disclosure of which is hereby incorporated.
This catalyst comprises: a) a support comprising a porous mineral matrix,
boron or a boron compound and phosphorous or a phosphorous compound, and
b) at least one metal or metal compound from group VIB of the periodic
table and at least one metal or metal compound from group VIII of the
periodic table, in which the sum of the quantities of boron and
phosphorous, respectively expressed as the weight of boron trioxide
(B.sub.2 O.sub.3) and phosphorous pentoxide (P.sub.2 O.sub.5) with respect
to the weight of the support, is about 5% to 15%, preferably about 8% to
12% and advantageously about 8% to 11.5%, the atomic ratio of boron to
phosphorous (B/P) being about 1.05:1 to 2:1, preferably about 1.1:1 to
1.8:1. Advantageously, at least 40% and preferably at least 50% of the
total pore volume of the finished catalyst is contained in pores with an
average diameter of more than 13 nanometers.
The catalyst preferably has a total pore volume in the range 0.38 to 0.51
cm.sup.3 .times.g.sup.-1.
The quantity of group VIB metals or metal compounds contained in the
catalyst is normally such that the atomic ratio of phosphorous to the
group VIB metal or metals (P/VIB) is about 0.5:1 to 1.5:1, preferably
about 0.7:1 to 0.9:1.
The respective quantities of group VIB metal or metals and group VIII metal
or metals contained in the catalyst are normally such that the atomic
ratio of group VIII metal or metals to group VIB metal or metals
(VIII/VIB) is about 0.3:1 to 0.7:1, preferably about 0.3:1 to about
0.45:1.
The quantity by weight of the metals contained in the finished catalyst,
expressed as the weight of metal with respect to the weight of the
finished catalyst, is normally about 2% to 30%, preferably about 5% to
25%, for the group VIB metal or metals, and about 0.1% to about 15%, more
particularly about 0.1% to 5%, for the group VIII metal or metals, and
preferably about 0.15% to 3% in the case of noble group VIII metals (Pt,
Pd, Ru, Rh, Os, Ir) and about 0.5% to 15%, preferably about 1% to 10%, in
the case of non noble group VIII metals (Fe, Co, Ni).
In step b), the mineral support can be selected from the group formed by
alumina, silica, silica-aluminas, zeolites, titanium oxide, magnesia,
boron oxide, zirconia, clays and mixtures of at least two of these mineral
compounds. The support preferably comprises at least one halogen selected
from the group formed by chlorine, fluorine, iodine and bromine,
preferably chlorine and fluorine. In an advantageous embodiment, the
support comprises chlorine and fluorine. The quantity of halogen is
normally about 0.5% to about 15% by weight with respect to the weight of
the support. The support is normally alumina. The halogen is normally
introduced into the support by the corresponding acid halide and the noble
metal, preferably platinum or palladium is introduced, for example, from
aqueous solutions of their salts or compounds such as hexachloroplatinic
acid in the case of platinum.
The quantity of noble metal (preferably Pt or Pd) in the catalyst in step
b) is preferably about 0.01% to 10%, usually about 0.01% to 5%, and
generally about 0.03% to 3%, expressed as the weight of metal with respect
to the weight of finished catalyst.
A particularly advantageous catalyst is described in FR-A-2 240 905, the
disclosure of which is hereby incorporated. It comprises a noble metal,
alumina, and a halogen, and is prepared by mixing the aluminous support
with a noble metal compound and a reducing agent with formula AlX.sub.y
R.sub.3-y where y is 1, 3/2 or 2, X is a halogen and R is a monovalent
hydrocarbon radical.
A further highly suitable catalyst is that described in U.S. Pat. No.
4,225,461. It comprises a noble metal and a halogen and is prepared in a
particular manner.
The following examples illustrate the invention without limiting its scope.
EXAMPLE 1
A straight run gas oil cut was used. Its characteristics are shown in Table
1. Its sulphur content was 1.44%.
This gas oil cut was treated in a two-step sequence:
A first step with a catalyst containing, in the form of the oxide, about 3%
of nickel, 16.5% of molybdenum and 6% of P.sub.2 O.sub.5 on alumina. This
first step was for deep desulphurisation and deep denitrogenation of the
gas oil cut.
A second step with a catalyst containing about 0.6% of platinum on alumina.
This second step was essentially for deep dearomatisation of the effluent
from the first step, but also to further reduce the sulphur content.
The first step was carried out in a hydrotreatment pilot unit. This
comprised two reactors in series which could contain up to 20 l of
catalyst in a fixed bed. The unit comprised a compressor for recycling
hydrogen. The fluids were in downflow mode in each reactor. The unit was
provided with an in-line steam stripping column for stripping the effluent
from the reaction which was thereby completely freed of the H.sub.2 S and
NH.sub.3 formed during the reaction.
5 l of the same catalyst was charged into each reactor of the pilot
reactor.
Deep desulphurisation and deep denitrogenation of the gas oil cut was
carried out in this unit under the following operating conditions:
HSV=1.5 h.sup.-1 ;
Total pressure=50 bar (10 bar=1 MPa);
H.sub.2 recycle=400 normal liters H.sub.2 /liter of feed (NI/l);
Temperature=340.degree. C.
A product was obtained which had been deeply desulphurised (sulphur content
below 50 ppm) and very deeply denitrogenated (nitrogen content below 6
ppm).
These characteristics are shown in Table 1. The material balance is shown
in Table 2.
The effluent was retained for pilot tests of the second step.
The second step was carried out in a smaller pilot unit comprising a 1 l
reactor with fluid upflow. The unit did not comprise a recycling
compressor.
1 l of catalyst was charged into this unit in a fixed bed.
The operating conditions were as follows:
HSV=6h.sup.-1 ;
Total pressure=50 bar;
H.sub.2 recycle=400 Nl H.sub.2 liter of feed;
Temperature=300.degree. C.
A product was obtained which had been very deeply dearomatised (aromatics
content below 5%) which had a very high cetane number (65).
These characteristics are shown in Table 1.
The material balance is shown in Table 2. No gas formation was detected
during the operation. The whole of the effluent could be sold as a very
high quality fuel cut.
TABLE No 1
______________________________________
Feed and effluent analysis, 1.sup.st and 2.sup.nd step
Feed
Properties SR gas oil 1.sup.st step
2.sup.nd step
______________________________________
15/4 density
0.852 0.830 0.824
Refractive index
1.4748 1.4600 1.454
Pour point .degree. C.
-3 -3 -6
Aniline point .degree. C.
71.7 79.1 86.7
Sulphur, ppm
14400 30 4
Nitrogen, ppm
110 6 6
Aromatics, ppm
30 22 2
Motor cetane
56 61 65
number
D86: IP, .degree. C.
223 205 205
D86: 95% v, .degree. C.
375 365 359
______________________________________
(D86 indicates the ASTMD86 method).
TABLE No 2
______________________________________
Material balance
1.sup.st and 2.sup.nd step
Wt %/feed 1.sup.st step
2.sup.nd step
______________________________________
H.sub.2 S 1.53 0.01
NH.sub.3 0.01 0.00
C1 0.01 0.00
C2 0.01 0.00
C3 0.02 0.00
C4 0.02 0.00
C5+ 99.14 100.49
Total 100.74 100.50
______________________________________
EXAMPLE 2
A catalytically cracked gas oil cut (LCO) was used. Its characteristics are
shown in Table 3. Its sulphur content was 1.56%.
This gas oil cut was treated in a two-step sequence:
A first step with a catalyst containing, in the form of the oxide, about 3%
of nickel, 16.5% of molybdenum and 6% of P.sub.2 O.sub.5 on alumina. This
first step was for deep desulphurisation and deep denitrogenation of the
gas oil cut.
A second step with a catalyst containing about 0.6% of platinum on alumina.
This second step was essentially for deep dearomatisation of the effluent
from the first step, but also to further reduce the sulphur and nitrogen
content.
The first step was carried out in a hydrotreatment pilot unit. This
comprised two reactors in series which could contain up to 20 l of
catalyst. The unit comprised a compressor for recycling hydrogen. The
fluids were in downflow mode in each reactor. The unit was provided with
an in-line steam stripping column for stripping the effluent from the
reaction which was thereby completely freed of the H.sub.2 S and NH.sub.3
formed during the reaction. 5 l of the same catalyst was charged into each
reactor of the pilot reactor.
Deep desulphurisation and deep denitrogenation of the gas oil cut was
carried out in this unit under the following operating conditions:
HSV=1 h.sup.-1 ;
Total pressure=80 bar (10 bar=1 MPa);
H.sub.2 recycle =400 Nl H.sub.2 /liter of feed;
Temperature=375.degree. C.
A product was obtained which had been deeply desulphurised (sulphur content
below 50 ppm) and very deeply denitrogenated (nitrogen content below 6
ppm).
These characteristics are shown in Table 3. The material balance is shown
in Table 4.
The effluent was retained for pilot tests of the second step.
The second step was carried out in a smaller pilot unit comprising a 1 l
reactor with fluid upflow. The unit did not comprise a recycling
compressor.
11 of catalyst was charged into this unit in a fixed bed.
The operating conditions were as follows:
HSV=4h.sup.-1 ;
Total pressure=50 bar;
H.sub.2 recycle =4001 H.sub.2 /l of feed;
Temperature=300.degree. C.
A product was obtained which had been very deeply dearomatised (aromatics
content below 5%) which had a cetane number of 54.
These characteristics are shown in Table 3.
The material balance is shown in Table 4. No gas formation was detected
during the operation. The whole of the effluent could be upgraded as a
very high quality fuel cut.
TABLE No 3
______________________________________
Feed and effluent analysis, 1.sup.st and 2.sup.nd step
Feed
Properties LCO 1.sup.st step
2.sup.nd step
______________________________________
15/4 density
0.942 0.873 0.857
Refractive index
1.5417 1.4818 1.4676
Pour point .degree. C.
3 3 3
Aniline point .degree. C.
37 62 76
Sulphur, m 15600 30 5
Nitrogen,ppm
1089 16 8
Aromatics, ppm
72 32 4
Motor cetane
27 45 54
number
D86: IP, .degree. C.
184 147 174
D86: 95% v, .degree. C.
394 382 380
______________________________________
TABLE No 4
______________________________________
Material balance
1.sup.st and 2.sup.nd step
Wt %/feed 1.sup.st step
2.sup.nd step
______________________________________
H.sub.2 S 1.66 0.00
NH.sub.3 0.13 0.00
C1 0.08 0.00
C2 0.08 0.00
C3 0.06 0.00
C4 0.05 0.00
C5+ 100.36 100.92
Total 102.42 100.93
______________________________________
EXAMPLE 3
The same feed as that treated in Example 2 was used, under the same HSV,
total pressure, H.sub.2 recycle and temperature conditions in each of the
steps, the only difference being that in the first step a catalyst
containing, in its oxide form, about 3% of nickel, 15% of molybdenum, 5%
of P.sub.2 O.sub.5 and 3.5% of B.sub.2 O.sub.3 on alumina was used, and in
the second step a catalyst containing about 0.6% of platinum, 1% of
chlorine and 1% of fluorine on alumina was used. The material balance in
each of the steps was the same as that given in Example 2, Table 4. An
analysis of the effluent from the 1.sup.st and 2.sup.nd steps is shown in
the Table below.
______________________________________
Feed
Properties LCO 1.sup.st step
2.sup.nd step
______________________________________
15/4 density
0.942 0.873 0.856
Refractive index
1.5417 1.4816 1.4666
Pour point .degree. C.
3 3 3
Aniline point .degree. C.
37 62 77
Sulphur, ppm
15600 21 4
Nitrogen, ppm
1089 8 4
Aromatics, ppm
72 32 3
Motor cetane
27 45 55
number
D86: IP, .degree. C.
184 147 174
D86: 95% v, .degree. C.
394 382 380
______________________________________
This example shows the effect of using a catalyst containing boron in the
1.sup.st step and also shows the influence of using a catalyst containing
both chlorine and fluorine in the 2.sup.nd step.
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